Safety valve device

ABSTRACT

A safety valve device for a milking installation for milking milk-producing animals having a first valve with a first port and with a first port connector, a second valve with a second port and with a second port connector, a third valve with a third port and a third port connector, a drive, a common actuator, and at least one valve spring, and arranged so that the first port connector of the first valve is in fluid communication with the second port connector of the second valve, and the safety valve device can be moved between a first switching position, in which the first valve and the second valve are closed in order to block the first port and the second port and the third valve, is open a transition position, in which the first valve, the second valve and the third valve are closed, and a second switching position, in which the first valve and the second valve are open to connect the first port to the second port and the third valve is closed to block the third port.

FIELD AND BACKGROUND OF THE INVENTION

The invention relates to a safety valve device used in a milking installation, in particular for the automatic milking of milk-producing animals, for example cows, sheep, goats etc.

The automatic milking process may be performed by means of so-called milking robots. The safety valve device is provided for protecting and sealing off the lines in which so-called “good milk” (for example, milk intended for sale or feeding to calves) is conducted, and also the “good milk” itself, from undesired media, for example cleaning and flushing media, from lines conducting so-called “bad milk” (for example, adulterated milk), and also for preventing undesired media from being drawn in.

It is necessary to observe and adhere to relevant national regulations and guidelines, for example the American FDA guidelines, which apply to milking installations and milking facilities which come into contact with milk.

Such a safety valve arrangement is also referred to as a “block-bleed-block valve arrangement”. Here, a medium flows through a cavity. The cavity can be closed off at one end by means of a first valve and at another end by means of a second valve. Depending on the flow direction, the valves are referred to as inlet and outlet valves. The cavity itself is provided, for aeration purposes, with a ventilation valve. In a throughflow position, the first and second valves are open so as to permit a flow of the medium through the first and second valves and through the cavity. Here, the ventilation valve is closed. If the first and second valves are closed in order to assume the ventilation position, the ventilation valve must remain closed until the first and second valves are completely closed. Only then can the ventilation valve be opened for the purpose of ventilating the cavity. This also applies in the reverse situation, that is to say when the safety valve device is switched over from the ventilation position into the throughflow position.

WO 2011/028293 A2 describes a safety valve for an automatic milking installation.

Owing to the ever increasing demands in particular for high throughput rates and continuous, low-maintenance operation, or operation with long maintenance intervals, in the case of modern milking installations or milking robots which are complex and expensive, there is a need for improved safety valve devices.

SUMMARY OF THE INVENTION

Against this background, it is the object of the invention to provide an improved safety valve device.

A safety valve device according to the invention for a milking installation for milking milk-producing animals includes a first valve with a first port and with a first port connector, a second valve with a second port and with a second port connector, a third valve with a third port and a third port connector, a drive, an actuator, and at least one valve spring, the first port connector of the first valve being connected to the second port connector of the second valve, and the safety valve device being designed such that it can be adjusted from a first switching position, in which the first valve and the second valve are closed in order to block the first port and the second port and the third valve is open to vent to atmospheric pressure or at least a pressure less than the pressure inside the first and second valves, passing through a transition position, in which the first valve, the second valve and the third valve are closed, into a second switching position, in which the first valve and the second valve are open in order to connect the first port to the second port via the port connectors and the third valve is closed in order to block the third port, and back. The first valve, the second valve and the third valve have a common actuator and a common drive which is coupled to (“operatively engaged with”) the common actuator.

It is thus advantageously achieved that the first, second and third valves, with only one actuator and only one drive, require less structural space than the case of the prior art, which provides one drive for each valve.

Furthermore, the electrical control is simplified because one common actuator is provided. During the actuation of the safety valve device, the actuator is adjusted by the drive and, owing to its mechanical design, transmits the movement to the individual valves such that the ventilation position and the throughflow position are reliably assumed, wherein the transition position is reliably passed through.

In one embodiment, the first valve, the second valve and the third valve have in each case one valve element which interacts with (“engages”) in each case one valve seat. A defined separation of the three valves can be achieved in this way.

It is also provided that the valve seats are constituent parts of a common valve housing and communicate with an interior of the common valve housing, the valve housing forming, by way of the interior, the port connectors of the valves. No further assembly of the three valves with respect to one another, that is to say by way of their port connectors, is necessary. Furthermore, for assembly, it is advantageous if the common valve housing has at least two housing parts which are connected to one another.

In a further embodiment, the common actuator is configured with a stroke composed of two ranges, the first range of the stroke being assigned to the adjustment of the safety device from the first switching position into the transition position, and the second range of the stroke being assigned to the adjustment of the safety device from the transition position into the second switching position and vice versa. In this way, it is possible to realize simple mechanical control of the switching phase of the safety valve device without additional outlay for electrical or electronic control. Furthermore, this can result in a direct (in the case of an electric drive) or indirect (in the case of a pneumatic drive with compressed-air generation by electrical means) saving of electrical energy.

For this purpose, it is provided that the common actuator is designed such that, in the first range of its stroke, it closes the third valve and maintains the closed state of the first valve and of the second valve, and in the second range, it opens the first valve and the second valve and maintains the closed state of the third valve and vice versa. It is thus possible to provide a common actuator for actuating all of the valves.

For this purpose, the common actuator has an actuation portion for coupling to (the term “coupling” is sometimes used herein interchangeably with “operatively engaged with” and merely references a connection or other operational relationship between two elements) the first valve, an actuation portion for coupling to the second valve, and an actuation portion for coupling to the third valve. It is thus also possible for the individual valves, depending on the construction thereof, to be coupled independently of one another in different ways to the common actuator. For example, mechanical and reliable control can be realized in a simple manner by means of guides and stops.

In one embodiment, the common actuator is arranged outside the common valve housing. This permits simple assembly and maintenance.

In this regard, the common actuator may be guided in an adjustable manner by means of an actuator guide on a frame and/or at least one guide element of the safety valve device. This permits a compact design.

In yet a further embodiment, the common actuator is preloaded (the term “preloaded” is sometimes used herein interchangeably with “biased”) toward the ventilation position by means of at least one actuator spring, in the ventilation position the first valve being preloaded (“biased”) toward a closed position by means of a valve spring and the second valve being preloaded (“biased”) toward a closed position by means of a valve spring, and in the ventilation position the third valve being preloaded (“biased”) into an open position by means of a valve spring which is connected to the actuator. This spring-controlled mechanism makes it possible for the two switching positions, ventilation position and throughflow position, and the transition position in the switching phase to be reproduced and assumed in a reliable manner.

An advantageously simple assembly is attained if the actuator has at least two actuation elements which are connected to and can be released again from one another, one actuation element having an actuation portion for coupling to the first valve and another actuation portion for coupling to the second valve, and the other actuation element having an actuation portion for coupling to the third valve.

In an alternative embodiment, it is provided that the common actuator comprises an actuation body, two actuation elements, and three actuation arms, wherein each of the three actuation arms is coupled to in each case one of the valves.

Here, one actuation element is coupled to the actuation body, and the other actuation element is coupled by way of one end to the former actuation element and by way of the other end to the drive. This gives rise to a space-saving arrangement.

In a further embodiment, the actuation body is arranged with the three actuation arms within the common valve housing. This yields the particular advantage of a space-saving arrangement. Furthermore, in this way, the drive may be arranged on the valve housing such that the actuator is arranged partly in a drive housing, on the one hand, and partly in the valve housing, on the other hand.

In yet a further embodiment, the actuation body is coupled to the actuation arms, each actuation arm being coupled to in each case one valve element. In this way, that portion of the actuation arm which is coupled to the valve element may form a constituent part of the respective valve, resulting in a simple and compact arrangement.

In one embodiment, the actuation body may be produced in one piece with the actuation arms and with at least one actuation element of the actuation elements. Here, the material may be a plastics material, a metal or a combination of these. It is self-evidently also possible for the actuator to be formed entirely in one piece or for the actuator to be formed as a welded structure composed of a food-safe metal, for example a correspondingly weldable high-grade steel.

In yet a further embodiment, it is provided that the valve elements of the first and second valves point in the opposite direction to the valve element of the third valve. Simple mechanical control of the different switching positions is possible in this way.

In one embodiment, each valve is assigned, for interaction, at least one secondary sealing element and at least one main sealing element. Simple setting of the different switching positions is possible in this way.

It is also provided that each valve element has at least one secondary sealing element and at least one main sealing element. It is thus possible for a doubled sealing action in the ventilation position and in the throughflow position of the one or more respectively closed valve(s), and also the transition position, to be realized in a simple manner.

In an alternative embodiment, the at least one secondary sealing element and the at least one main sealing element are arranged in a valve housing and/or a housing part. It is thus possible to realize a simplified design, because the valve elements need not be fitted with the sealing elements.

It is also provided that the at least one secondary sealing element and the at least one main sealing element are arranged concentrically with respect to and spaced apart from one another. It is thus made possible for the respective valve to be sealed off, on the one hand, by means of the at least one secondary sealing element and the at least one main sealing element, and on the other hand, by means of only the at least one secondary sealing element.

In one embodiment, the at least one secondary sealing element and the at least one main sealing element are provided as separate components. It is self-evidently also possible, in an alternative embodiment, for these to be formed in one piece with a common body, wherein they are then for example different sealing portions, for example beads, lips etc., of the common body. It is also conceivable for the at least one secondary sealing element and the at least one main sealing element and the common body to be formed as a two-component or multi-component injection-molded part.

In a further embodiment, at least one of the valve elements has an intermediate element and a retaining element. This design makes a particularly advantageous design possible, wherein the at least one main sealing element is arranged between the respectively associated actuation arm and the intermediate element, and the at least one secondary sealing element is arranged between the intermediate element and the retaining element. A secure and captive fit of the sealing elements is thus ensured.

A further embodiment provides that, in the ventilation position, the main sealing elements of the first valve and of the second valve interact with the respective valve seat so as to form a closed state of the associated valve, and that the main sealing element and the secondary sealing element of the third valve are not in engagement with the associated valve seat of the third valve so as to form an open state of the third valve.

Here, it is also provided that, in the throughflow position, the main sealing elements and the secondary sealing elements of the first and second valves interact, whilst not in engagement with the respective valve seat, so as to form an open state of the associated valve, and that the main sealing element and the secondary sealing element of the third valve interact with the associated valve seat of the third valve so as to form a closed state of the third valve.

For the transition position, it is provided here that, in the transition position, the secondary sealing elements of the first and second valves interact with the respective valve seat so as to form a closed state of the associated valve, and that the secondary sealing element of the third valve interacts with the associated valve seat of the third valve so as to form a closed state of the third valve. It is thus possible for the switching positions and the transition position to be realized mechanically and in a simple manner by means of one drive and one actuator.

Furthermore, by means of the valve springs and the actuator spring, it is possible for one switching position to be in the form of a safety position. This means that a safe switching position is automatically assumed in the event of failure of the energy supply for the actuation of the drive of the safety valve device. For example, the ventilation position may be the safety position.

In another embodiment, the common actuator comprises two actuation elements, an actuation plate, a central body with two actuation bars, and two actuation arms, wherein each of the two actuation arms is coupled to in each case one of the two valves, wherein the actuation element is coupled via an actuation portion to a third valve. This gives rise to a simple design.

It is also provided that the central body is arranged with the two actuation arms within the common valve housing. This permits a compact design.

In yet a further embodiment, each actuation arm is coupled to in each case one valve element, and the actuation portion is coupled to a third valve element. This allows the valves to be actuated independently of one another, wherein actuation may be performed from only one side.

For this purpose, it is provided that the actuation arms are jointly actuable, the actuation portion being movable independently of the actuation arms.

In yet a further embodiment, the valve elements of the first and second valves point in the opposite direction to the valve element of the third valve. It is thus advantageously possible for the third valve to be utilized as a ventilation valve with a downward outlet for collecting liquids.

Furthermore, in a further embodiment, it is provided that the safety valve device is equipped with at least one sensor device for detecting the respective switching position. This may be realized, for example, by virtue of the actuator being coupled to a sensor actuator which interacts with a sensor. Here, because the actuator is coupled to the valves, the actuator position is detected as the switching position of the safety valve device.

A safety valve arrangement of a milking installation for milking milk-producing animals has at least one safety valve arrangement as described above. For simplified maintenance and ease of assembly and disassembly, the safety valve arrangement may for example be formed in the manner of a drawer or the like.

Further advantages and details will emerge from the exemplary embodiment illustrated in the figures of the drawing, in which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of an exemplary usage situation with a conventional safety valve device;

FIGS. 2 and 3 show, in schematic circuit-symbol-based illustrations, the safety valve device in different switching positions;

FIG. 4 is a schematic circuit-symbol-based illustration of a safety valve device according to the invention, in a first switching position;

FIG. 5 is a schematic circuit-symbol-based illustration of the safety valve device according to the invention as per FIG. 4, in a second switching position;

FIGS. 6a through 6c are schematic sectional illustrations of a first exemplary embodiment of the safety valve device according to the invention as per FIGS. 4 and 5, in different switching positions;

FIG. 7 shows the first exemplary embodiment of the safety valve device according to the invention as per FIGS. 6a-6c in a view from the rear;

FIGS. 8a through 8c show schematic side views of a second exemplary embodiment of the safety valve device according to the invention as per FIGS. 4 and 5, in different switching positions;

FIG. 9 shows the second exemplary embodiment of the safety valve device according to the invention as per FIGS. 8a-8c in a perspective view from the rear;

FIGS. 10 through 12 show schematic sectional views of the second exemplary embodiment of the safety valve device according to the invention as per FIGS. 8a-8c , in different switching positions;

FIG. 13 shows a schematic perspective view of a safety valve arrangement;

FIG. 14 shows a schematic, perspective and partially sectional view of a third exemplary embodiment of the safety valve device according to the invention as per FIGS. 4 and 5;

FIGS. 15 through 17 show schematic sectional views of the third exemplary embodiment of the safety valve device according to the invention as per FIG. 14, in different switching positions;

FIGS. 18 through 20 show schematic sectional views of variants of the third exemplary embodiment of the safety valve device according to the invention as per FIG. 14;

FIGS. 21a through 21b show schematic views of an actuator of the third exemplary embodiment of the safety valve device according to the invention as per FIG. 14;

FIG. 22 shows a schematic sectional view of a valve element of the third exemplary embodiment of the safety valve device according to the invention as per FIG. 14;

FIG. 23 shows a schematic sectional view of a further variant of the third exemplary embodiment of the safety valve device according to the invention as per FIG. 14;

FIG. 24 is a schematic, perspective exploded illustration of components of the further variant as per FIG. 23; and

FIGS. 25a through 25c show schematic sectional views of a fourth exemplary embodiment of the safety valve device according to the invention as per FIGS. 4 and 5, in different switching positions.

DETAILED DESCRIPTION OF THE DRAWINGS

In the figures, identical or similar functional elements and components are denoted by the same reference numerals.

The expressions “top” and “bottom” relate to the respective arrangement in the figures. An installation position, for example upside-down, sideways or in some other position, is not restricted to these designations.

FIG. 1 is a schematic illustration of an exemplary usage situation with a conventional safety valve device 1′. FIGS. 2 and 3 show, in schematic circuit-symbol-based illustrations, the safety valve device 1′ in different switching positions.

The illustration shows two safety valve devices 1′ of a milking installation for milking milk-producing animals, for example cows. Two such safety valve devices 1′ are provided for each teat on an udder of a milk-producing animal. The safety valve device 1′ serves for preventing undesired media, such as contaminated milk, sanitizers, dirt, and debris, from being inadvertently drawn out of a “bad milk” line (in this case for example a port line 5 b) into a “good milk” line (in this case for example a port line 5 a and 5 c).

The safety valve device 1′ comprises three individual valves 2′, 3′ and 4′, specifically a first valve 2′, a second valve 3′ and a third valve 4′. The first valve 2′ and the second valve 3′ are also referred to as “block valves”. Depending on the flow direction of the medium flowing through, the first valve 2′ is designated as inlet valve and the second valve 3′ is designated as outlet valve, or vice versa. The third valve 4′ is normally designated as “bleed valve”. The three valves 2′, 3′ and 4′ are connected to one another such that the first valve 2′ and the second valve 3′ are connected in series in terms of flow, wherein the third valve 4′ is connected to the port connector of the first valve 2′ and of the second valve 3′. Thus, the safety valve device 1′, which is also referred to as a “block-bleed-block valve”, is formed.

The first valve 2′ has a first port 2′a and a first port connector 2′b. In the same way, the second valve 3′ is provided with a second port 3′a and a second port connector 3′b. The third valve 4′ has a third port 4′a and a third port connector 4′b.

The first port connector 2′b of the first valve 2′ is connected to the second port connector 3′b of the second valve 3′ and to the third port connector 4′b of the third valve 4′. The port connectors 2′b, 3′b and 4′b form a cavity which can be traversed by a flow of a medium.

The safety valve device 1′ can be adjusted or switched over from a first switching position, referred to as ventilation position, into a second switching position, referred to as throughflow position, and back.

In the ventilation position, the first valve 2′ and the second valve 3′ are closed, and the third valve 4′ is open so that reduced or atmospheric pressure is available at the third port 4′a.

In the throughflow position, the third valve 4′ is closed, wherein the first port 2′a and the second port 3′a are connected by the open first valve 2′ and the open second valve 3′.

In the exemplary arrangement shown in FIG. 1, two safety valve devices 1′ are provided, one of which, at the bottom left in FIG. 1, is connected via the first port 2′a by means of a port line 5 to a vessel 5A, for example for storing “bad milk”. The second port 3′a is connected via a port line 5 a to the first port 2′a of the other safety valve device 1′ and via a second port line 5 b to a milk receptacle of a milking appliance (not shown). The second port 3′a of the other safety valve device 1′ is connected via a further port line 5 c to a further vessel 5B (not shown in any more detail) which is provided for example for storing “good milk”. The good milk may pass through a conventional chiller and a milk meter 5C before being stored in the good milk vessel 5B.

The conventional safety valve device 1′ is shown in schematically simplified form in FIG. 2 and FIG. 3 by means of circuit symbols. Each valve 2′, 3′, 4′ has a drive 6-2′, 6-3′, 6-4′ which is for example a pneumatic cylinder. Each drive 6-2′, 6-3′, 6-4′ is coupled to an actuator 7-2′, 7-3′, 7-4′ which, in this case, is provided with in each case one valve spring 8-2′, 8-3′, 8-4′, for example a pressure spring to “bias” the valve toward a desired direction or position. Each actuator 7-2′, 7-3′, 7-4′ is coupled to a valve block 9-2′, 9-3′, 9-4′. The valve blocks 9-2′, 9-3′, 9-4′ here have the respective ports 2′a, 3′a, 4′a and 2′b, 3′b, 4′b.

FIG. 2 shows the first switching position (ventilation position) of the safety valve device V. In the first switching position, the first valve 2′ and the second valve 3′ are closed. The third valve 4′ is open and connects the port connectors 2′b, 3′b and 4′b to the third port 4′a. The third port 4′a may for example be connected to a further line (not shown) which communicates for example with the atmosphere or with a vessel.

In the ventilation position, the ports 2′a and 3′a are closed and no flow can pass through these. The third port 4′a is open, such that the port connectors 2′b, 3′b and 4′b can be “ventilated”.

FIG. 3 shows the second switching position of the safety valve device 1′, in which the first valve 2′ and the second valve 3′ are open. Here, the third valve 4′ is closed.

If the first switching position, the ventilation position, of the safety valve device 1′ the first valve 2′ and the second valve 3′ are both closed and the third valve 4′ is open to provide a vent between the first valve 2′ and the second valve 3′. In the second switching position, the throughflow position, the valves 2′ and 3′, also referred to as throughflow valves, are both open and the third valve 4′ is closed. A switchover phase is of importance here. The first valve 2′ and the second valve 3′ may be opened, in order to assume the throughflow position, only after the third valve 4′ has been closed. Likewise, the third valve 4′ may be opened, for the ventilation position, only after the first valve 2′ and the second valve 3′ have been closed.

In the throughflow position, the ports 2′a and 3′a are open and are connected to one another by the port connectors 2′b and 3′b, such that a flow can pass from the first port 2′a to the second port 3′a through the third valve 4′, which is now closed.

In the conventional safety valve device 1′ with the three individual valves 2′, 3′, 4′, the two switching positions with the switchover phases are regulated through control of the individual drives 6-2′, 6-3′, 6-4′.

FIG. 4 is a schematic circuit-symbol-based illustration of a safety valve device 10 according to the invention in the first switching position, that is to say in the ventilation position. FIG. 5 is a schematic circuit-symbol-based illustration of the safety valve device 10 according to the invention as per FIG. 4 in a second switching position, that is to say in the throughflow position.

By contrast to the conventional safety valve device 1′, the safety valve device 10 according to the invention has only one drive 6, the latter being coupled to one common actuator 7 and to one valve spring 8, for example a pressure spring. Furthermore, the safety valve device 10 according to the invention comprises a valve block 9-2 of a first valve 2, a valve block 9-3 of a second valve 3 and a valve block 9-4 of a third valve 4. The valve blocks 9-2, 9-3, 9-4 are coupled to the common actuator 7. For this purpose, the common actuator 7 has an actuation portion 7 a for the actuation of the valve block 9-2 of the first valve 2, an actuation portion 7 b for the actuation of the valve block 9-3 of the second valve 3, and an actuation portion 7 c for the actuation of the valve block 9-4 of the third valve 4.

In the ventilation position shown in FIG. 4, the valve block 9-2 of the first valve 2 and the valve block 9-3 of the second valve 3 are closed, wherein the valve block 9-4 of the third valve 4 is open. In the ventilation position, no flow can pass from the first port 2 a to the second port 3 a, and vice versa.

When the safety valve device 10 situated in the ventilation position as per FIG. 4 is actuated, the valve block 9-2 of the first valve 2 and the valve block 9-3 of the second valve 3 are held (biased) closed by the valve spring 8, for example a pressure spring, until the valve block 9-4 of the third valve 4 is closed. Only thereafter do the valve block 9-2 of the first valve 2 and the valve block 9-3 of the second valve 3 open so as to assume the throughflow position shown in FIG. 5. In the throughflow position, a flow can pass from the first port 2 a to/through the second port 3 a, because the third port 4 a is closed.

Conversely, the valve block 9-2 of the first valve 2 and the valve block 9-3 of the second valve 3 are initially closed until the valve block 9-4 of the third valve 4 then opens so as to assume the ventilation position.

The assumption of the two switching positions with the associated switchover phases is controlled by mechanical means, as will be described below.

In this regard, FIGS. 6a-6c are schematic sectional illustrations of a first exemplary embodiment of the safety valve device 10 according to the invention as per FIGS. 4 and 5, in different switching positions. Here, FIG. 6a shows the first or ventilation position. FIG. 6b illustrates a switchover phase or transition position, and FIG. 6c shows the second or throughflow position.

FIG. 7 shows the first exemplary embodiment of the safety valve device 10 according to the invention as per FIGS. 6a-6c in a view from the rear.

A direction z is used to indicate adjustment directions for the actuation of the safety valve device 10. A direction z1 denotes the actuation direction for assuming the throughflow position, wherein an opposite direction z2 denotes the actuation direction for assuming the ventilation position.

In the first exemplary embodiment, the safety valve device 10 according to the invention has three valves 2, 3, 4 having in each case one valve block 9-2, 9-3, 9-4, a common drive 6 (see FIG. 7), an actuator 7, biasing valve springs 15, 16, 17 (or other biasing device can be used in the place of any of the springs described herein) and a common valve housing 20 with an interior 20 a.

The first valve 2 has the first port 2 a, the second valve 3 has the second port 3 a, and the third valve 4 has the third port 4 a. As seen in FIG. 6c , the port connectors 2 b, 3 b, 4 b of the valves 2, 3, 4 are realized in this case by the common valve housing 20 with the interior 20 a.

The safety valve device 10 is assigned a frame 18 which bears and accommodates functional parts and enables the safety valve device 10 to be mounted on appliances (not shown). Furthermore, the actuator 7 is arranged in the frame 18 so as to be guided in an actuator guide 19.

Here, the actuator 7 comprises two columns which extend in the z direction and which are connected at the upper ends thereof by a transverse connector extending at right angles thereto. The lower ends of the columns are connected to a lower transverse connector which is arranged parallel to the upper transverse connector. Lateral ends of the lower transverse connector project in each case to the left and to the right from the columns and extend in each case over a valve 2, 3. Here, that end of the lower transverse connector which is arranged in the region of the first valve 2 forms an actuation portion 7 a for the first valve 2. The other end of the lower transverse connector, which is arranged in the region of the second valve 3, forms an actuation portion 7 b for the second valve 3. A projection as an actuation portion 7 c for the third valve 4 projects in an upwardly extending manner in the z1 direction in the center of the lower transverse connector, between the columns. In the ventilation position shown in FIG. 6a , the lower transverse connector of the actuator 7 rests with the bottom sides of the actuation portions 7 a and 7 b on the valve housing 20.

The first valve 2 comprises a valve element 12 with a valve shank 12 a and a valve spring 15 with a valve spring disk 15 a. The valve spring disk 15 a is fixedly connected to the valve shank 12 a. The valve element 12 interacts with a valve seat 12 b which is arranged within the valve housing 20, in the interior 20 a thereof. The valve element 12 serves for connecting the port 2 a to the interior 20 a of the valve housing 20 and, in the ventilation position shown in FIG. 6a , closes off a connection between the interior 20 a of the valve housing 20 and the first port 2 a. The valve shank 12 a is held, so as to be guided in a longitudinally displaceable manner, in the valve housing 20 by way of seals (not illustrated) and in the frame 18. These illustrations are merely schematic, and an implementation is readily conceivable to a person skilled in the art.

Here, the valve spring 15 is a pressure spring and surrounds the valve shank 12 a within the frame 18 and is arranged between the valve spring disk 15 a and the frame 18. In the ventilation position, the valve spring disk 15 a is arranged at a distance from an actuation portion 7 a of the actuator 7. The valve spring 15 exerts a preload (“bias”) on the valve element 12 and presses the latter into the valve seat 12 b, whereby, in the ventilation position, the first valve 12 is closed.

Similarly, the second valve 3 comprises a valve element 13 with a valve shank 13 a, and a valve spring 16 with a valve spring disk 16 a. The valve spring disk 16 a is fixedly connected to the valve shank 16 a. The valve element 13 interacts with (“engages”) a valve seat 13 b which is also arranged within the valve housing 20, in the interior 20 a thereof. In the ventilation position shown in FIG. 6a , the valve element 13 closes off a connection between the interior 20 a of the valve housing 20 and the first port 3 a. The valve element 13 serves for connecting the port 3 a to the interior 20 a of the valve housing 20. Like the valve shank 12 a of the first valve 2, the valve shank 13 a is held in a guided manner in the valve housing 20.

In this case, too, the valve spring 16 is preferably a pressure spring and surrounds the valve shank 13 a within the frame 18, wherein the valve spring 16 is arranged between the valve spring disk 16 a and the frame 18. In the ventilation position, the valve spring disk 16 a is arranged at the same distance from an actuation portion 7 b of the actuator 7 as the valve spring disk 15 a of the first valve 2. The valve spring 16 exerts a preload (“bias”) on the valve element 13 and presses the latter into the valve seat 13 b, whereby, in the ventilation position, the second valve 12 is closed.

The valve elements 12 and 13 are in the form of valve disks which are fastened in each case to one end of the associated valve shank 12 a, 13 a and which interact by way of their front sides with the respective valve seat 12 b, 13 b. Here, the front side refers to that side of the valve element 12, 13 which is situated opposite the respective valve shank 12 a, 13 a.

The third valve 4 comprises a valve element 14 with a valve shank 14 a, and a valve spring 17 with a valve spring disk 17 a. The valve element 14 interacts with a valve seat 14 b which is arranged in the wall of the valve housing 20, wherein that side of the valve element 14 to which the valve shank 14 a is fastened interacts with the valve seat 14 b. Here, the valve element 14 is arranged below, and on the outside of, the valve housing 20. The valve shank 14 a extends through the valve seat 14 b, and through the upper wall, situated thereabove, of the valve housing 20, into a receptacle of the actuation portion 7 c of the actuator 7. The upper end of the valve shank 14 a of the third valve 4 projects in the z direction out of the actuation portion 7 c of the actuator 7 and is fixedly connected to the valve spring disk 17 a. The valve spring 17 in the form of a pressure spring is arranged between the valve spring disk 17 a and the upper end of the actuation portion 7 c of the actuator 7.

Furthermore, at least one actuator spring 17 b, for example also a pressure spring, is arranged around the actuation portion 7 c of the actuator 7 and the valve spring 17, which actuator spring is supported on the central part of the lower transverse connector of the actuator 7 and an upper inner side of the frame 18. The actuator spring 17 b exerts a preload (“bias”) force on the actuator 7 in the z2 direction such that the actuator 7 is preloaded into the ventilation position and, here, rests on the valve housing 20.

The actuator 7, with the columns and transverse connectors including the actuation portions 7 a, 7 b, 7 c thereof, may for example be a unipartite plastics injection-molded part. Other materials and/or combinations of different materials are self-evidently also possible. It is likewise possible for the actuator 7 to be assembled from different components which are connected to one another.

The valve element 14 serves for connecting the interior 20 a of the valve housing 20 to the port 4 a (FIGS. 1 through 5), and in the throughflow position shown in FIG. 6c , closes off a connection between the interior 20 a of the valve housing 20 and the port 4 a (FIG. 7).

In the ventilation position shown in FIG. 6a , the valve seat 14 b is not closed off by the valve element 14. The third valve 4 is open. Here, the valve spring 17 is connected by way of in each case one end to the actuation portion 7 c and to the valve spring disk 17 a such that, in the ventilation position, in which the actuator 7 is pressed against the valve housing 20 by the actuator spring 17 b, the valve spring disk 17 a of the third valve 4 is pulled and preloaded in the z2 direction by the valve spring 17 such that the valve element 14 of the third valve 4 does not close off the valve seat 14 b, that is to say the third valve 4 remains in the open position.

When the safety valve device 10 is actuated by adjustment of the actuator 7 in the actuation direction z1 by means of the drive 6 (FIG. 7), firstly, the valve spring 17 of the third valve 4 is pressed against the valve spring disk 17 a by the associated actuation portion 7 c of the actuator 7, whereby the valve shank 14 a with the valve element 14 is adjusted in the z1 direction such that the valve element 14 of the third valve 4 closes off the valve seat 14 b. The interior 20 a of the valve housing 20 is thus closed off because the first valve 2 and the second valve 3 remain closed. This is the case in the transition position shown in FIG. 6b because the actuation portions 7 a and 7 b of the actuator 7 do not immediately actuate the respectively associated valve spring disk 15 a of the first valve 2 and the valve spring disk 16 a of the second valve 3, but must firstly cover the distance that exists in the z1 direction. At the end of the transition position in FIG. 6b , the actuation portions 7 a and 7 b of the actuator 7 are in contact with the valve spring disk 15 a of the first valve 2 and with the valve spring disk 16 a of the second valve 3. Thus, in the transition position, no air can pass into the interior 20 a.

With further actuation, that is to say adjustment of the actuator 7 in the z1 direction, the valve spring disk 15 a of the first valve 2 and the valve spring disk 16 a of the second valve 3 are also adjusted in the z1 direction by the associated actuation portions 7 a and 7 b. Since the valve spring disk 15 a of the first valve 2 and the valve spring disk 16 a of the second valve 3 are fixedly connected to the respective valve shank 15 a, 16 a of the associated valve element 12, 13, the first valve 2 and the second valve 3 are opened, that is to say the valve elements 12 and 13 open the respective valve seat 12 b and 13 b. As a result, the interior 20 a of the valve housing 20 is connected to the ports 2 a and 3 a. The valve seat 14 b of the third valve 4 remains closed, wherein the valve spring 17 of the third valve 4 is compressed with even greater intensity as a result of the further actuation travel of the actuation portion 7 c in the z1 direction, which results in an intensification of the closure fit of the valve seat 14 b. Thus, the open position illustrated in FIG. 6c is finally attained.

When the actuator 7 is actuated in order to reassume the ventilation position, the actuator is actuated in the z2 direction. Then, the transition position as per FIG. 6b is firstly assumed, and finally the ventilation position as per FIG. 6a is assumed. The valve actuation sequence is the reverse of that described above.

FIGS. 8a-8c show schematic side views of a second exemplary embodiment of the safety valve device 10 according to the invention as per FIGS. 4 and 5, in different switching positions. FIG. 9 shows the second exemplary embodiment of the safety valve device 10 according to the invention as per FIGS. 8a-8c in a perspective view from the rear. In this regard, FIGS. 10-12 show schematic sectional views of the second exemplary embodiment of the safety valve device 10 according to the invention as per FIGS. 8a-8c , in different switching positions.

FIG. 8a illustrates the second exemplary embodiment in a side view, in the ventilation position. In this regard, FIG. 10 shows a sectional view along line X. FIG. 8b shows a transition position, and FIG. 11 illustrates the sectional view along line XI. FIG. 8c shows the throughflow position. The associated sectional view along line XII is illustrated in FIG. 12.

In the second exemplary embodiment, the safety valve device 10 according to the invention comprises three valves 2, 3, 4, a common drive 6, a common actuator 70, valve springs 15, 16, 17, a frame 18, and a common valve housing 20 with an interior 20 a.

In this second exemplary embodiment, too, the first valve 2 has the first port 2 a, the second valve 3 has the second port 3 a, and the third valve 4 has the third port 4 a, wherein here, too, the port connectors 2 b, 3 b, 4 b of the valves 2, 3, 4 are realized by the common valve housing 20 with the interior 20 a.

As seen in FIGS. 8 though 8 b, the frame 18 has two frame parts 18 a and 18 b which are connected to one another for example by fastening means, for example screws. An upper frame part 18 a is Z-shaped, for example in the form of a punched and bent part composed of metal, and on its upper leg 18 c bears the drive 6 which is for example a pneumatic cylinder. The lower leg of the upper frame part 18 a is connected to the plate-shaped lower frame part 18 b, which bears the valve housing 20.

Here, the valve housing 20 has an upper housing part 21 and a lower housing part 22. The housing parts 21 and 22 are connected to one another in an encircling manner. The connection must be formed in accordance with respective national regulations and standards. The connection may for example be realized by means of screws. An ultrasound welding process is also possible, though it may not satisfy USA FDA standards the joining methods and arrangements are possible within the scope of the invention. The housing parts 21 and 22 enclose an interior 20 a. The upper housing part 21 has the ports 2 a and 3 a of the valves 2 and 3 with the associated valve seats 12 b and 13 b. Furthermore, the upper housing part 21 is configured as a bracket for two bar-shaped guide elements 19 a of the actuator guide 19.

The first port 2 a communicates with the valve seat 12 b of the first valve 2. On the opposite side of the upper housing part 21, the second port 3 a of the second valve 3 communicates with the associated valve seat 13 b. The third port 4 a with the valve seat 14 b of the third valve 4 is arranged in the center of the lower housing part 22.

The first valve 2 comprises a valve element 12 with a valve shank 12 a, which in this case is of hollow form, and the valve spring 15, which is inserted into the cavity of the valve shank 12 a so as to extend over approximately half of the length of the valve shank 12 a and which rests by way of its lower end on a shoulder in the valve shank 12 a. The valve spring 15 is supported by way of the upper end on the bottom side of the upper leg 18 c of the frame part 18 a. The valve spring 15 is in this case a pressure spring.

The valve shank 12 a is held, so as to be guided in a longitudinally displaceable manner, in the upper housing part 21, and is sealed off with respect to the upper housing part 21 by means of a seal 23, for example an O-ring. The seal 23 is arranged in a recess of the upper housing part 21.

The upper region of the valve shank 12 a, into which the valve spring 15 is inserted, is referred to as connection portion 12 c and is defined axially by a collar-like actuation stop 12 d on the upper end of the valve shank 12 a and by a rest stop 12 e arranged at a distance below the actuation stop. The stops 12 d and 12 e are fixedly connected to the valve shank 12 a. The function of the stops will be explained in more detail below. The connection portion 12 c is coupled to the common actuator 70 via an actuation portion 72 a, which will also be discussed in more detail further below.

The second valve 3 likewise comprises a valve element 13 with a valve shank 13 a, which is of hollow form, and the valve spring 16, which rests in the cavity of the valve shank 13 a in the same way as the valve spring 15 in the valve shank 12 a of the first valve 2. The valve spring 16 is also supported by way of the upper end on the bottom side of the upper leg 18 c of the frame 18. In this case, too, the valve spring 16 is a pressure spring.

Like the valve shank 12 a, the valve shank 13 a is held, so as to be guided in a longitudinally displaceable manner, in the upper housing part 21, and is sealed off with respect to the upper housing part 21 by means of a seal 23, for example an O-ring. The seal 23 is arranged in a recess of the upper housing part 21.

The upper region of the valve shank 13 a, into which the valve spring 16 is inserted, is referred to as connection portion 13 c and is defined axially by a collar-like actuation stop 13 d on the upper end of the valve shank 13 a and by a rest stop 13 e arranged at a distance below the actuation stop. The stops 13 d and 13 e are fixedly connected to the valve shank 13 a. The function of the stops will be explained in more detail below. The connection portion 13 c is coupled to the common actuator 70 via an actuation portion 72 b, which will also be discussed in more detail further below.

The valve elements 12 and 13 are formed in the manner of valve disks which are fastened in each case to one end of the associated valve shank 12 a, 13 a and which, by way of their front sides, interact with the respective valve seat 12 b, 13 b in the upper housing part 21 from the outside. Here, the front side is to be understood to mean that side of the valve element 12, 13 which is situated opposite the respective valve shank 12 a, 13 a.

Here, the third valve 4 comprises a valve element 14 with a valve shank 14 a, which is of hollow form, and the valve spring 17 which is inserted into the cavity of the valve shank 13 a and which rests by way of its upper end on a base of the valve shank 14 a. The base of the valve shank 14 a is connected to the valve element 14. Here, the valve element 14 is arranged on the bottom side of the lower housing part 22 of the valve housing 20 and points in the z direction toward the other valve elements 12 and 13. By way of its lower end, the valve spring 17 is inserted into a receptacle 71 c of an actuation portion 71 a of the common actuator 70 and is supported on the base of the receptacle 71 c. The valve shank 14 a engages around the receptacle 71 c. The valve shank 14 a is guided, so as to be longitudinally displaceable in the z direction, by the receptacle 71 c and is held by the latter in a way which is not illustrated in any more detail. In this case, the valve spring 17 is a pressure spring.

In this exemplary embodiment, the common actuator 70 comprises two parts which are connected to one another for assembly purposes. A first actuation element 71 is arranged at the bottom, and a second actuation element 72 forms the upper part of the actuator 70. The first actuation element 71 is of L-shaped form. A short leg is formed by the actuation portion 71 a, which has a downwardly pointing surface 71 b and which is fixedly connected to the long leg extending in the z direction and which is additionally stiffened by means of triangular side portions connected to the short leg and to the long leg. The rear sides of the parts of the common actuator 70 are furthermore stiffened by means of ribs. This is shown in FIG. 9 by way of example for the rear sides of the first and second actuation elements 71 and 72. This is also easily conceivable for the surface 71 b of the bottom side of the actuation portion 71 a. The common actuator 70 may be produced from plastics injection-molded parts, from punched and bent parts composed of metal, or from combinations of these.

The second actuation element 72 is coupled to the drive 6 in a way which is not illustrated in any more detail. An actuator spring (not shown here) with the same function as in the first exemplary embodiment as per FIGS. 6a-6c is arranged within the drive 6. A sensor device 25 (not explained in any more detail) for detecting the respective switching position of the safety valve device 10 is arranged in the region of the coupling. The sensor device 25 may for example be a constituent part of the drive 6. Only one sensor device 25 is necessary, because in the respective switching position, the valves 2, 3 and 4 are positively closed.

A safety position is provided in which the drive 6 is deployed in the z2 direction. This may be effected for example by the actuator spring or other biasing device. Here, the first valve 2 and the second valve 3 are closed, and the third valve 4 is open. The safety position corresponds to the ventilation position.

Furthermore, the second actuation element 72 is provided, in its central portion, with two guide bores through which the bar-like guide elements 19 a of the actuator guide 19 extend. In this way, the second actuation element 72 and thus the common actuator 70 are guided and held so as to be longitudinally displaceable in the z direction.

The actuation portion 72 a is attached to the central portion of the second actuation element 72 on one side (on the left-hand side in FIGS. 10-12), and the actuation portion 72 b is attached to the central portion on the right-hand side. The actuation portions 72 a and 72 b are for example of fork-shaped form and engage in each case around the associated connection portion 12 c and 13 c of the respective valve 2 and 3. In the ventilation position illustrated in FIGS. 8a and 10, the actuation portion 72 a rests on the upper side of the rest stop 12 e of the first valve 2. In this case, the actuation portion 72 b rests on the upper side of the rest stop 13 e of the second valve 3.

In the ventilation position shown in FIGS. 8a and 10, the valve element 12 of the first valve 2 and the valve element 13 of the second valve 3 are pressed into the associated valve seat 12 b and 13 b by their respective valve springs 15, 16. The valves 2 and 3 are thus closed.

If the drive 6 is now activated in order to switch the safety valve device 10 from the ventilation position into the throughflow position, the common actuator 70 is moved by the drive 6 in the z1 direction. Here, firstly, the valve element 14 of the third valve 4 is pressed against the valve seat 14 b. The third valve 4 is thus closed. (FIG. 11.) At the same time, the fork-shaped actuation portions 72 a and 72 b move upward on the respective connection portions 12 c and 13 c in the z1 direction, wherein the valve shanks 12 a and 13 a are not adjusted because the actuation portions 72 a and 72 b move away from the rest stops 12 e and 13 e. In the transition position illustrated in FIGS. 8b and 11, the third valve 4 is closed. The first valve 2 and the second valve 3 are likewise closed. The actuation portion 72 a is now in contact with the bottom side of the actuation stop 12 d of the first valve 2, and the actuation portion 72 b is in contact with the bottom side of the actuation stop 13 d of the second valve 3. Thus, in the transition position, no air can pass into the interior 20 a.

The common actuator 70 is moved further in the z1 direction by the drive 6 in order to assume the throughflow position. Here, the valve shank 12 a of the first valve 2 is also moved in the z1 direction, by way of the actuation stop 12 d, by the actuation portion 72 a. Likewise, the actuation portion 72 b moves the valve shank 13 a of the second valve 3 in the z1 direction. As a result, the first valve 2 and the second valve 3 are opened. The valve spring 17 of the third valve 4, which remains closed, is compressed further and presses the valve element 14 more intensely into the valve seat 14 b. The throughflow position is shown in FIGS. 8c and 12.

The overall stroke of the common actuator 70 is composed of two ranges. In the first range, the actuator 70 is adjusted upward in the z1 direction and closes the third valve 4. During the phase, the actuation portions 72 a and 72 b move along the connection portions 12 c and 13 c of the valve shanks 12 a and 13 a. Only when the third valve 4 is closed in the transition position are the first valve 2 and the second valve 3 opened in a second range of the stroke of the actuator 70.

The first range of the stroke of the actuator 70 can be predefined by the distance between the top side of the actuation portions 72 a, 72 b and the bottom side of the actuation stops 12 d, 13 d.

The position of the valve shank 14 a with the valve element 14 of the third valve 4 in relation to the top side of the actuation portion 71 a, or the preload (“bias”) of the valve spring 17 of the third valve 4, can be adjusted in the z direction by means of an adjusting element 24, for example a screw in a bore 71 d with a thread.

FIG. 13 shows a schematic perspective view of a safety valve arrangement 26. The safety valve arrangement 26 has in this case four safety valve devices 10 according to the second exemplary embodiment. The four safety valve devices 10 are mounted, with their longitudinal sides parallel to one another, on a support unit 27. The arrangement can be exchanged in its entirety for maintenance or exchange purposes, for example, and thus facilitates maintenance work. In this regard, the safety valve arrangement 26 may also be formed in the manner of a drawer. The safety valve arrangement 26 which is shown is merely an example. Other arrangements with different unit quantities and with different designs are self-evidently also possible.

FIG. 14 shows a schematic, perspective and partially sectional view of a third exemplary embodiment of the safety valve device 11 according to the invention as per FIGS. 4 and 5. FIGS. 15-17 show schematic sectional views of the third exemplary embodiment of the safety valve device 11 according to the invention as per FIG. 14, in different switching positions.

FIG. 15 shows the ventilation position of the safety valve device 11, wherein the ventilation position is simultaneously also the safety position of the safety valve device 11. FIG. 16 shows the transition position, and FIG. 17 illustrates the throughflow position.

The safety valve device 11 according to the third exemplary embodiment comprises the first valve 2, the second valve 3, the third valve 4, a common drive 6, a common actuator 700, a common valve spring 717, and a common valve housing 20 with an interior 20 a.

In the third exemplary embodiment, it is also the case that the first valve 2 has the first port 2 a, the second valve 3 has the second port 3 a, and the third valve 4 has the third port 4 a. It is likewise the case here that the port connectors 2 b, 3 b, 4 b of the valves 2, 3, 4 are realized by the common valve housing 20 with the interior 20 a.

The drive 6 is arranged in a hollow circular cylindrical drive housing 6 a with a base 6 b. The drive 6 may for example be in the form of a pneumatic cylinder, this not being illustrated in any more detail here. The drive housing 6 a is connected via a conical hollow part to the top side of the upper housing part 21 of the valve housing 20. The conical hollow part is in this case formed in one piece with the drive housing 6 a, wherein a connection portion on the bottom side of the conical hollow part has a smaller diameter than a connection portion at the connection point of the conical hollow part to the circular cylindrical drive housing 6 a. Thus, the space between the ports 2 a and 3 a is utilized, wherein the distance between the ports can be kept small.

The upper housing part 21 is connected at its left-hand end to the first port 2 a of the first valve 2 and at its right-hand end to the second port 3 a of the second valve 3.

The lower housing part 22 of the valve housing 20 is connected to the upper housing part 21 in a similar manner to that in the second exemplary embodiment as per FIGS. 8a -12, for example by means of screws, as already explained above. In the third exemplary embodiment, the lower housing part 22 is formed so as to be funnel-shaped in the downward direction, wherein the third port 4 a of the third valve 4 is arranged at the lower point and is connected to the lower housing part 22.

The third port 4 a points downward, whereas the first port 2 a points upward and to the left at approximately 45° with respect to an imaginary horizontal line. Mirror-symmetrically with respect to the first port 2 a, the second port 3 a points upward and to the right at approximately 45° with respect to an imaginary horizontal line. The ports 2 a, 3 a, 4 a communicate with the interior 20 a of the valve housing 20. At their connection points to the valve housing 20, all of the ports 2 a, 3 a, 4 a are provided with a circular cylindrical portion. The circular cylindrical portion of the first port 2 a forms a valve seat 12 b of the first valve 2, the circular cylindrical portion of the second port 3 a forms a valve seat 13 b of the second valve 3, and the circular cylindrical portion of the third port 4 a forms a valve seat 14 b of the third valve 3.

The first valve 2 comprises a valve element 12 with a secondary sealing element 121 and with a main sealing element 122. In this embodiment, the valve element 12 has a cylindrical body, on the outer circumference of which the sealing elements 121, 122 are mounted in corresponding receptacles. The secondary sealing element 121 is arranged on the upper end of the valve element 12, and the main sealing element 122 is mounted on the valve element 12 at a distance below the secondary sealing element 121.

The valve element 12 of the first valve 2 interacts with the circular cylindrical valve seat 12 b in the first port 2 a and, depending on the position of the first valve 2, separates the first port 2 a from, or connects the first port 2 a to, the interior 20 a of the valve housing 20. Here, the valve element 12 is guided in the valve seat 12 b so as to be displaceable in the z direction.

The second valve 3 is constructed in the same way as the first valve 2 and comprises a valve element 13 with a secondary sealing element 131 and a main sealing element 132. The valve element 13 also has a cylindrical body, on the outer circumference of which the sealing elements 131, 132 are mounted in corresponding receptacles. The secondary sealing element 131 is arranged on the upper end of the valve element 13, and the main sealing element 132 is mounted on the valve element 13 at a distance below the secondary sealing element 131.

The valve element 13 of the first valve 3 interacts with the circular cylindrical valve seat 13 b in the second port 3 a and, depending on the position of the second valve 3, separates the first port 3 a from, or connects the first port 3 a to, the interior 20 a of the valve housing 20. Here, the valve element 13 is guided in the valve seat 13 b so as to be displaceable in the z direction.

Here, the first valve element 12 and the second valve element 13 are arranged in parallel.

The third valve 4 is also constructed in the same way as the first valve 2 and the second valve 3 and comprises a valve element 14 with a secondary sealing element 141 and with a main sealing element 142. The valve element 14 also has a cylindrical body, on the outer circumference of which the sealing elements 141, 142 are mounted in corresponding receptacles. Here, the secondary sealing element 141 is arranged on the lower end of the valve element 14, and the main sealing element 142 is mounted on the valve element 14 at a distance above the secondary sealing element 141.

The valve element 14 of the third valve 4 interacts with the circular cylindrical valve seat 14 b in the third port 4 a and, depending on the position of the third valve 4, separates the third port 4 a from, or connects the third port 4 a to, the interior 20 a of the valve housing 20. Here, the valve element 14 is guided in the valve seat 14 b so as to be displaceable in the z direction.

In this exemplary embodiment, the secondary sealing elements 121, 131, 141 and the main sealing elements 122, 132, 142 are separate components. They may however also be sealing portions, for example beads, lips etc., of a common body with which they are formed in one piece, this not being illustrated but being easily conceivable.

Whereas the valve elements 12 and 13 point upward, the third valve element 14 is arranged so as to point downward. The central axes of all of the valve elements 12, 13, 14 run substantially parallel. The central axes of the valve seats 12 b, 13 b, 14 b are also arranged parallel to one another. Each valve element 12, 13, 14 is arranged centrally in the respectively associated valve seat 12 b, 13 b, 14 b.

All of the valve elements 12, 13, 14 are connected to the common actuator 700 and can be adjusted with the latter in the z direction.

The common actuator 700 comprises an actuation body 770, two actuation elements 771, 772, and three actuation arms 712, 713, 714.

The actuation arms 712 and 713 are attached to the actuation body 770 so as to point laterally upward and to the left and upward and to the right, wherein the actuation arm 714 is attached to the actuation body 770 so as to extend vertically downward in the z direction. The valve element 12 of the first valve 2 is attached to the free end of the actuation arm 712. In the same way, the valve element 13 of the second valve 3 is attached to the free end of the actuation arm 713. Also, the free end of the actuation arm 714 is connected to the valve element 14 of the third valve 4. Here, all of the central axes of the valve elements 12, 13, 14 are arranged parallel to one another and to a central axis of the first actuation element 771 of the actuator 700.

The first actuation element 771, of bar-shaped form, is attached to the top side of the actuation body 770 and extends upward in the z1 direction through an opening 28 in the upper wall of the upper housing part 21, through a sealed-off bearing 29, as far as approximately the middle of the conical hollow part of the drive housing 6.

The upper end of the first actuation element 771 is of peg-like form and is provided with an annular sensor actuator 25 b of a sensor device 25. The sensor actuator 25 b is fixedly connected to the first actuation element 771 and interacts with a sensor 25 a of the sensor device 25 in order to detect the switching position of the safety valve device 11. Here, the sensor actuator 25 b may for example be an annular magnet.

The peg-like end of the first actuation element 771 is received in a corresponding receptacle of a lower end of the second, likewise bar-shaped actuation element 772 of the actuator 700, and connects the first actuation element 771 and the second actuation element 772.

The second actuation element 772 extends in the z1 direction through the base 6 b of the drive housing 6 and through the major part of the drive housing 6. The valve spring disk 717 a is fixedly attached to the upper end of the second actuation element 772. The common valve spring 717 is arranged around the second actuation element 772 and is supported by way of its lower end on the base 6 b of the drive housing 6 and by way of its upper end on the bottom side of the valve spring disk 717 a with a predefinable preload (“bias”).

Here, the valve spring 717 is a pressure spring and presses the common actuator 700 upward in the z1 direction by axial exertion of force on the valve spring disk 717 a. In this way, the safety position or ventilation position of the safety valve arrangement 11, illustrated in FIG. 15, is assumed. In the ventilation position, the first valve 2 and the second valve 3 are closed, wherein the third valve 4 is open. The closed position of the first valve 2 is realized by virtue of the fact that the valve element 12 is arranged within the valve seat 12 b, wherein the secondary sealing element 121 and main sealing element 122 interact with the valve seat 12 b and separate the first port 2 a from the interior 20 a of the valve housing 20. The interaction of the secondary sealing element 121 and of the main sealing element 122 with the valve seat 12 b consists in that the secondary sealing element 121 bears sealingly by way of its encircling seal lip 31 (see FIG. 22) or seal surface, and the main sealing element 122 bears sealingly by way of its encircling seal surface 30 (see also FIG. 22), against the inner surface of the valve seat 12 b.

In the same way, the closed position of the second valve 3 is realized by virtue of the fact that the valve element 13 is arranged within the valve seat 13 b, wherein the secondary sealing element 131 and main sealing element 132 interact with the valve seat 13 b and separate the first port 3 a from the interior 20 a of the valve housing 20. The interaction of the secondary sealing element 131 and of the main sealing element 132 with the valve seat 13 b consists in that the secondary sealing element 131 bears sealingly by way of its encircling seal lip 31 (see FIG. 22) or seal surface, and the main sealing element 132 bears sealingly by way of its encircling seal surface 30 (see also FIG. 22), against the inner surface of the valve seat 13 b.

The valve element 14 of the third valve 4, with its sealing elements 141, 142, is pulled all the way out of the valve seat 14 b, wherein the third port 4 a is connected to the interior 20 a of the valve housing 20. For the closed position of the third valve 4, it is also true that the interaction of the secondary sealing element 141 and of the main sealing element 142 with the valve seat 14 b consists in that the secondary sealing element 141 bears sealingly by way of its encircling seal lip 31 (see FIG. 22) or seal surface, and the main sealing element 142 bears sealingly by way of its encircling seal surface 30 (see also FIG. 22), against the inner surface of the valve seat 14 b.

The construction of the valve elements 12, 13, 14 with the associated sealing elements 121, 122; 131, 132; 141, 142 will be explained in more detail below in conjunction with FIG. 22.

In the ventilation position, the ventilation position is detected by means of the sensor device 25 such that the sensor actuator 25 b interacts with the sensor 25 a, wherein the sensor 25 a, for example a Hall sensor, produces a corresponding electrical signal, which need not be explained in any more detail.

When the safety valve device 11 is actuated in order to assume the throughflow position proceeding from the ventilation position, the common actuator 700 is adjusted by the drive 6 in the z2 direction counter to the preload (“bias”) force of the common valve spring 717. Here, the transition position illustrated in FIG. 16 is firstly passed through.

The sensor actuator 25 b is outside the range of the sensor 25 a, and the latter thus no longer generates a signal.

In the transition position, the common actuator 700 moves the actuation body 770, and the actuation arms 712, 713, 714 attached thereto, downward in the z2 direction. Here, it is firstly the case that the main sealing elements 122, 132 of the first and second valves 2, 3 pass out of the respective valve seat 12 b, 13 b into the interior 20 a of the valve housing, wherein however the secondary sealing elements 121, 131 of the first and second valves 2, 3 remain in the respective valve seat 12 b, 13 b and continue to close the respective valve 2, 3.

Here, at the same time, the secondary sealing element 141 of the third valve 4 enters the associated valve seat 14 b and thus also closes the third valve 4.

Thus, in the transition position, all of the valves 2, 3, 4 are closed.

When the throughflow position shown in FIG. 17 is assumed, the secondary sealing elements 121, 131 of the first and second valves 2, 3 have also moved out of the respective valve seats 12 b, 13 b. As a result, the first valve 2 and the second valve 3 are open. The secondary sealing element 141 of the third valve 4 has been moved further into the valve seat 14 b in the z2 direction. At the same time, the main sealing element 142 of the third valve 4 is also in contact with the inner wall of the valve seat 14 b of the third valve 4. Thus, the third valve 4 remains closed in the throughflow position.

In FIGS. 15-17, the transitions between the ports 2 a, 3 a, 4 a and the housing walls of the valve housing 20 are formed in each case with a chamfer against which the outer surface of the respective main sealing element 122, 132, 142 bears. Other configurations are self-evidently possible and will be explained in more detail below.

Through the arrangement of in each case two sealing elements 121, 122; 131, 132; 141, 142 spaced apart axially from one another, the formation of the transition position is possible in a simple manner. Thus, in the transition position, no air can pass into the interior 20 a.

FIGS. 18-20 illustrate schematic sectional views of variants of the third exemplary embodiment of the safety valve device 11 according to the invention as per FIG. 14.

In the variant of the safety valve device 11 a as per FIG. 18, the ports 2 a and 3 a are arranged parallel to one another and to the central axis of the first actuation element 771. The transitions 20 b between the ports 2 a, 3 a, 4 a and the housing walls of the valve housing 20 are in this case formed in each case with a chamfer. The actuation arms 712 and 713 are arranged substantially horizontally.

In the variant of the safety valve device 11 b as per FIG. 19, the ports 2 a and 3 a are also arranged parallel to one another and to the central axis of the first actuation element 771. The transitions between the ports 2 a, 3 a, 4 a and the housing walls of the valve housing 20 have an internal structure 20 c which is of particularly streamlined form for the medium flowing through. The actuation arms 712 and 713 are arranged substantially horizontally, this also being referred to as a barbell shape.

Finally, FIG. 20 shows a variant of the safety valve device 11 c in which the ports 2 a and 3 a are arranged parallel to one another and with a very small spacing to one another and to the central axis of the first actuation element 771. The transitions between the ports 2 a, 3 a, 4 a and the housing walls of the valve housing 20 have an internal structure 20 d which is of particularly streamlined form for the medium flowing through. The sealing elements 12, 13, 14 have smaller diameters than in the preceding variants, and are formed so as to be slightly longer axially.

FIGS. 21a and 21b show schematic views of the common actuator 700 of the third exemplary embodiment of the safety valve device 11 according to the invention as per FIG. 14.

In the perspective view of the common actuator 700 in FIG. 21a , it can be seen here that the actuation arms 712 and 713 protrude laterally and upward at an angle from the actuation body 770, wherein the actuation body 770 merges, in the upward direction, into the first actuation element 771, and in the downward direction, into the very short actuation arm 714. The actuation body 770, the first actuation element 771, and the actuation arms 712, 713, 714 are in this case formed in one piece, for example as a plastics injection-molded part composed of a food-safe plastic. It is self-evidently also possible for use to be made of a metal material, in particular a food-safe high-grade steel. The parts 770, 771, 712, 713, 714 are then welded to one another.

The side view in FIG. 21b shows, by way of example, weld seams between the above-mentioned metal parts and stiffening webs on the sides of the actuation arms 712, 713.

FIG. 22 illustrates a schematic sectional view of a valve element 12, 13, 14 of the third exemplary embodiment of the safety valve device 11 according to the invention as per FIG. 14.

Each valve element 12, 13, 14 has a secondary sealing element 121, 131, 141, a main sealing element 122, 132, 142, an intermediate element 754, and a retaining element 761. The main sealing element 122, 132, 142 is arranged between the end of the respective actuation arm 712, 713, 714 of the actuator 700 and the intermediate element 754. The secondary sealing element 121, 131, 141 is mounted between the intermediate element 754 and the retaining element 761. The end of the respective actuation arm 712, 713, 714 of the actuator 700, the intermediate element 754 and the retaining element 761 are connected to one another. In the case of a plastic, for example PPSU, the parts are connected to one another by means of an ultrasound welding process. In the case of metal or combinations, other connection techniques are self-evidently also possible. The respective actuation arm 712, 713, 714 may have a cavity 750. The intermediate element 754 may also have a cavity 760. The cavities 750 and 760 are arranged centrally with respect to one another and may, for example for connection and/or stiffening purposes, be provided for receiving a connecting element, for example a cylindrical part, which is not shown.

That side of the respective actuation arm 712, 713, 714 of the actuator 700 which points towards the respective intermediate element 754 is of conical form with a seal portion 751, the outer diameter of which increases toward the intermediate element 754. For receiving the main sealing element 122, 132, 142, there is formed into the seal portion 751 a recess 753 which has an encircling edge 752. The recess 753 corresponds to the shape of the respective main sealing element 122, 132, 142 and, in this case, is formed with a radius. Between the end of the respective actuation arm 712, 713, 714 and the side, connected thereto, of the intermediate element 754, and between the other side of the intermediate element 754 and the side, connected thereto, of the retaining element 761, there is provided in each case one centering means (shaft shoulder, receiving bore) for the components, the centering means not being shown in any more detail.

That end of the intermediate element 754 which points towards the end of the respective actuation arm 712, 713, 714 is provided with a recess 755 which also corresponds to the shape of the respective main sealing element 122, 132, 142 and which in this case, like the recess 753, is provided with a radius. The recess 755 is formed, like the recess 753, with an encircling edge 756.

The two recesses 753 and 755 serve to receive the main sealing element 122, 132, 142, which in this case is in the form of a round cord seal (O-ring) with a circular cross section and a seal surface 30. The edge 752 of the end of the respective actuation arm 712, 713, 714 and the edge 756 of the intermediate element 754 are designed so as to extend beyond the central point of the circular cross section of the main sealing element 122, 132, 142 and thereby fix and captively hold the latter when the respective valve element 12, 13, 14 is in the assembled state. That is to say, a cross-sectional area of the two recesses 753 and 755 which are situated together in the assembled state (as shown in FIG. 22) form a circle segment whose central angle is greater than 180°, in this case for example approximately 228°. Thus, a part of the cross-sectional area of the respective main sealing element 122, 132, 142 is surrounded with a form fit by the recesses 753 and 755.

The respective secondary sealing element 121, 131, 141 is arranged at the connection side between the intermediate element 754 and the retaining element 761. The secondary sealing element is received on the intermediate element 754 and on the retaining element 761 by mutually opposite encircling recesses 758, 759, 762 and 763. Here, the recesses 758 and 763 and in each case one encircling edge 757 of the intermediate element 754 and one encircling edge 764 of the retaining element 761 surround a part of the cross section of the respective secondary sealing element 121, 131, 141 with a form fit. The recesses 758 and 763 correspond to the outer contour, which they surround with a form fit, of edge surfaces 34 of the respective secondary sealing element 121, 131, 141, which in this case has a triangular cross section with a sealing lip 31, rounded seal edges 32 and a base side with a seal abutment 33. The ends of the base side form the rounded seal edges 32 and are connected in each case via one side to the sealing lip 31, which is situated opposite the base side. In the example shown here, an angle of the sealing lip 31 between the sides is approximately 90°.

That part of the cross section of the respective secondary sealing element 121, 131, 141 which is surrounded by the recesses 758 and 763 with a form fit is formed by the base side with the seal abutment 33, by the rounded seal edges 32 and by approximately in each case one quarter of the length of a respective side. In the assembled state, the recesses 759 and 762 correspond to the base side of the triangular cross section of the respective secondary sealing element 121, 131, 141, wherein the recesses 758 and 763 which are connected in each case to the recesses 759 and 762 correspond to the rounded seal edges 32 and the in each case approximately one quarter of the length of a respective side of the triangular cross section of the respective secondary sealing element 121, 131, 141.

In this way, in the assembled state of the respective valve element 12, 13, 14, the secondary sealing element 121, 131, 141 is fixed and captively retained. The retaining element 761 is, at its free end, of conical form with an obtuse angle.

During the assembly of the respective valve element 12, 13, 14, the sealing elements 121, 122; 131, 132; 141, 142 are installed between the corresponding components 712, 713, 714; 754 and 761.

The secondary sealing elements 121, 131, 141 may also be in the form of O-rings or geometric formations on the intermediate element 754 and/or retaining element 761. Two-component injection-molded embodiments are self-evidently also possible.

It is possible for all of the sealing elements 121, 122; 131, 132; 141, 142 or only the secondary sealing elements 121, 131, 141 or only the main sealing elements 122, 132, 142 to be formed from a fluoroelastomer material.

FIG. 23 shows a schematic sectional view of a further variant of the third exemplary embodiment of the safety valve device according to the invention as per FIG. 14. FIG. 24 is a schematic, perspective exploded illustration of components of the further variant as per FIG. 23.

FIG. 23 shows the throughflow position; the other switching positions have already been explained on the basis of the preceding descriptions.

By contrast to the third exemplary embodiment as per FIG. 24, the safety valve device 11 d in this variant firstly has the secondary sealing elements 121, 131, 141 and main sealing elements 122, 132, 142 arranged not on the respective valve element 12, 13, 14 but in each case in the valve housing 20. Secondly, instead of separate secondary sealing elements 121, 131, 141 and separate main sealing elements 122, 132, 142, the sealing elements are in this case each formed integrally, as sealing lips or sealing beads, on a common sealing body 120, 130, 140. Here, each valve element 12, 13, 14 has a sealing surface 212, 213, 214 which is in the form of a cylindrical surface and which interacts in each case with the secondary sealing elements 121, 131, 141 and main sealing elements 122, 132, 142 of the sealing bodies 120, 130, 140 in the different switching positions of the safety valve device 11 d, as already described above.

A further contrast consists in the construction. The valve housing 20 comprises the in this case upper housing part 21 with the ports 2 a and 3 a, the in this case lower housing part 22 with the port 14 a, an intermediate housing 22 a as a seal support and intermediate component, and a housing seal 22 b. The housing part 21 also has four fastening domes 35, provided in part with threaded bolts 35 a for fastening to a bracket (not shown). The sealing bodies 120 and 130 are inserted into the top side of the seal support 22 a, wherein the top side of the seal support 22 a is closed by the housing part 21. Here, guide domes 22 c of the seal support 22 a serve for centering the upper housing part 21, the guide domes for this purpose engaging with corresponding openings in the upper housing part 21. Furthermore, the opening 28 with the bearing 29 for the actuator 700 is formed in the housing part 21, as explained above.

The encircling housing seal 22 b is arranged between the bottom side of the seal support 22 a and the top side of the lower housing part 22. The third port 4 a is mounted, by way of a plate surrounding the latter, on the bottom side of the lower housing part 22, the third port 4 a having opposite inserted press-in nuts 36 a which interact with in each case one connection screw 36. This entire construction is held together by the connection screws 36, wherein these extend from the top side of the upper housing part 21 through suitable passage openings situated outside the housing interior 20 a and are screwed into the press-in nuts 36 a. In this way, all of the components of the safety valve device 11 d are held together in a fixed manner. The construction is simple to assemble and also to disassemble again.

FIGS. 25a-25c show schematic sectional views of a fourth exemplary embodiment of the safety valve device 10 a according to the invention as per FIGS. 4 and 5, in different switching positions. Here, FIG. 25a shows the ventilation position of the safety valve device 10 a, wherein the ventilation position is simultaneously also the safety position of the safety valve device 10 a. FIG. 25b shows the transition position, and FIG. 25c illustrates the throughflow position.

This fourth exemplary embodiment is similar both to the second exemplary embodiment as per FIGS. 10-12 and also to the third exemplary embodiment as per FIGS. 15-17.

The valve housing 20 with the interior 20 a has the ports 2 a and 3 a on the top side, wherein the port 4 a is arranged on the bottom side. By contrast to the second exemplary embodiment as per FIGS. 10-12, the valve element 14 of the third valve 4 is also actuated from above, that is to say from the same side as the other valve elements 2 and 3.

The valve elements 12 and 13 are arranged in each case on one end of an actuation arm 712, 713, as in the third exemplary embodiment. By contrast to the third exemplary embodiment, each valve element 12, 13 has an encircling seal body 120 a and 130 a in the form of a ring with circular cross section. Each seal body 120 a, 130 a interacts with a sealing seat 12 b, 13 b of the associated valve 2, 3.

By contrast to the third exemplary embodiment, the actuation arms 712, 713 are connected to one another via a central body 770 a which has a central passage opening 770 b. Furthermore, each actuation arm 712, 713 is connected, in the first third of its length as viewed from the central body 770 a, to an actuation bar 712 a, 713 a. The actuation bars 712 a, 713 a extend parallel to one another upward in the z direction, wherein the upper ends of the actuation bars 712 a, 713 a are connected by means of a horizontal actuation plate 715. The actuation bars 712 a, 713 a are guided and mounted in the top side of the valve housing 20 in bearings 29 and are sealed off with respect to the valve housing 20 in a way which is not shown in any more detail. Furthermore, on the top side of the valve housing 20, there is arranged a plate 20 e which has a spring abutment 20 f for an actuator spring 17 b.

The actuator spring 17 b is arranged with preload (“bias”) between the spring abutment 20 f and a spring abutment 715 a on the bottom side of the actuation plate 715, and presses the actuation plate 715 with the actuation bars 712 a, 713 a mounted thereon upward, such that in this ventilation position, the valves 2 and 3 are closed, as explained above.

The actuator 70 comprises a first actuation element 71 with a bar-shaped actuation portion 71 a and a second actuation element 72.

The third valve 4 interacts with the valve element 14 which, like the other valve elements 2, 3, also has a sealing body 140 a which interacts with the sealing seat 14 b of the third valve 4. Here, by contrast to the third exemplary embodiment, the valve element 14 is connected to the bar-shaped actuation portion 71 a of the actuator 70, wherein the valve element 14 is movable independently of the two other valve elements 12 and 13. The bar-shaped actuation portion 71 a extends centrally in the z direction through the passage opening 770 b of the central body 770 a, further upward through the wall of the valve housing 20, in which the actuation portion 71 a is guided in a bearing 29 and sealed off with respect to the valve housing 20, onward through the plate 20 e, and concentrically through the actuator spring 17 b into the actuation element 71. The first actuation element 71 has an internal receptacle for the upper end of the bar-shaped actuation portion 71 a, in which receptacle the actuation portion 71 a is connected in an axially locked manner to the first actuation element 71 in a connecting portion 71 g. The lower end of the first actuation element 71 is provided with a flange 71 e which serves as a spring disk for a valve spring 17.

The valve spring 17 is arranged concentrically around the tubular first actuation element 71 and, with preload (“bias”), between the top side of the flange 71 e of the first actuation element 71 and the bottom side of a flange 72 c of the actuation element 72. The upper end of the first actuation element 71 is received, so as to be displaceable in the z direction, in a receptacle 72 d of the actuation element 72.

In the safety position of the safety valve device 10 a shown in FIG. 25b , the second actuation element 72 has been adjusted downward in the z2 direction toward the valve housing 20, such that the flange 72 c rests on the top side of the actuation plate 715. Here, the first actuation element 71 with the bar-shaped actuation portion 71 a and the valve element 14 have also been adjusted in the z2 direction such that the valve element 14 closes the valve 4. Here, the valve spring 17 exerts a preload (“bias”) on the valve element 14.

In the throughflow position of the safety valve device 10 a shown in FIG. 25c , the second actuation element 72 has been adjusted further in the z2 direction toward the valve housing 20 such that, now, the actuation plate 715 has also been adjusted in the z2 direction counter to the force of the actuator spring 17 b, and via the actuation bars 712 a, 713 a has also adjusted the valve elements 12 and 13 in the z2 direction such that the valves 2 and 3 are open.

In the reverse actuation sequence, the springs 17 b and 17 serve initially for assuming the transition position and then for assuming the ventilation position.

The exemplary embodiments described above do not restrict the invention. The invention may be modified within the scope of the appended claims.

The valves 2, 3, 4 may also be composed in each case of two or more valves connected in parallel or in series.

It is for example conceivable for the valve springs 8, 8-2′, 8-3′, 8-4′, 15, 16, 17 to be composed in each case of two or more springs.

Instead of a valve spring 8, 8-2′, 8-3′, 8-4′, 15, 16, 17, 717, it is also possible to use some other type of force store element with a spring function.

The safety valve arrangement 26 (FIG. 13) is also not restricted to the safety valve devices 10, but may also have other embodiments, for example according to the third exemplary embodiment.

It is also possible for the common actuator 700 of the third exemplary embodiment to be produced in one piece, wherein the common actuator has no separate actuation elements 771 and 772.

Instead of the ends of the respective actuation arms 712, 713, 714 of the actuator 700, it is also possible in the third exemplary embodiment of the safety valve device 11 for corresponding separate receiving parts to be provided. The valve elements 12, 13, 14 may thus initially be manufactured separately and then mounted by way of the receiving parts on the ends of the respective actuation arm 712, 713, 714. 

The invention claimed is:
 1. A safety valve device for a milking installation for milking milk-producing animals, the safety valve comprising: a first valve; a second valve; a third valve; and a common actuator that moves the safety valve device between: a first switching position, in which the first valve and the second valve are closed, and the third valve is open; a transition position, in which the first valve, the second valve, and the third valve are closed; and a second switching position, in which the first valve and the second valve are open and the first valve is in fluid communication with the second valve and the third valve is closed, wherein the common actuator comprises: an actuation body joined to a first actuation element and operatively engaged with a second actuation element, and the actuation body is joined to the first actuation arm, a second actuation arm, and a third actuation arm, wherein each of the actuation arms is operatively engaged with a respective valve.
 2. The safety valve device of claim 1, wherein the second actuation element is operatively engaged with to the first actuation element.
 3. The safety valve device of claim 1, wherein the actuation body, the first actuation arm, the second actuation arm, and the third actuation arm are disposed within a common valve housing.
 4. The safety valve device of claim 1, and further comprising: a first valve element, a second valve element, and a third valve element, and wherein each actuation arm is operatively engaged with a respective valve element.
 5. The safety valve device of claim 1, wherein the actuation body is formed integrally with the first actuation arm, the second actuation arm, and the third actuation arm, and with the first actuation element.
 6. A safety valve device for a milking installation for milking milk-producing animals, the safety valve comprising: a first valve; a second valve; a third valve; and a common actuator that moves the safety valve device between: a first switching position, in which the first valve and the second valve are closed, and the third valve is open; a transition position, in which the first valve, the second valve, and the third valve are closed; and a second switching position, in which the first valve and the second valve are open and the first valve is in fluid communication with the second valve and the third valve is closed, wherein the first valve, the second valve, and the third valve each include a valve element and a valve seat engaging the valve element when the valve is closed, and wherein the valve element of the first valve and the valve element of the second valve are arranged in a direction that is opposite a direction of the valve element of the third valve.
 7. A safety valve device for a milking installation for milking milk-producing animals, the safety valve comprising: a first valve; a second valve; a third valve; and a common actuator that moves the safety valve device between: a first switching position, in which the first valve and the second valve are closed, and the third valve is open; a transition position, in which the first valve, the second valve, and the third valve are closed; and a second switching position, in which the first valve and the second valve are open and the first valve is in fluid communication with the second valve and the third valve is closed, and each valve comprises; a main sealing element; and a secondary sealing element.
 8. The safety valve device of claim 7, wherein the main sealing element seals a respective valve when the valve is closed; and the secondary sealing element seals a respective valve when the valve is at least partially closed.
 9. The safety valve of claim 7, wherein each valve comprises: a valve element and each valve element is joined to a respective secondary sealing element and main sealing element.
 10. The safety valve device of claim 9, wherein at least one of the valve elements comprises: an intermediate element; and a retaining element joined to the intermediate element.
 11. The safety valve device of claim 10, wherein the main sealing element is adjacent to the intermediate element, and wherein the secondary sealing element is arranged at least partially between the intermediate element and the retaining element.
 12. The safety valve device of claim 7, wherein the secondary sealing element and the main sealing element are arranged concentrically with respect to and spaced apart from one another.
 13. The safety valve device of claim 7, wherein the secondary sealing element and the main sealing element are formed separately one another.
 14. The safety valve device of 7, wherein, in the safety valve device first position, the main sealing elements of the first valve and of the second valve each engage a respective valve seat to close the valve, and the main sealing element and the secondary sealing element of the third valve are not engaged with a valve seat to thereby open the third valve.
 15. The safety valve device of claim 14, wherein, in the second safety valve device switching position, the main sealing elements and the secondary sealing elements of the first valve and the second valve are not engaged with a respective valve seat to thereby open the first valve and the second valve, and wherein the main sealing element and the secondary sealing element of the third valve are engaged with a valve seat of the third valve to close the third valve.
 16. The safety valve device of claim 14, wherein, in the safety valve device transition position, the secondary sealing elements of the first and second valves each engage a respective valve seat to close the first valve and the second valve, and the secondary sealing element of the third valve engages a valve seat of the third valve to close the third valve.
 17. A safety valve device for a milking installation for milking milk-producing animals, the safety valve comprising: a first valve; a second valve; a third valve; and a common actuator that moves the safety valve device between: a first switching position, in which the first valve and the second valve are closed, and the third valve is open; a transition position, in which the first valve, the second valve, and the third valve are closed; and a second switching position, in which the first valve and the second valve are open and the first valve is in fluid communication with the second valve and the third valve element is closed, wherein the common actuator comprises: a first actuation element; a second actuation element operatively engaged with the first actuation element; an actuation plate operatively engaged with the first actuation element in the transition position and in the second position, and operatively engaged with the second actuation element in the second position; a plurality of actuation bars operatively engaged with the actuation plate; a central body joined to the actuation bars; a first actuation arm and a second actuation arm, and each actuation arm is joined to the central body; an actuation portion operatively engaged with the first actuation element; and wherein the first actuation arm is operatively engaged with the first valve, the second actuation arm is operatively engaged with the second valve, and the first actuation element and the actuation portion are operatively engaged with the third valve.
 18. The safety valve device of claim 17, and further comprising: a common valve housing, wherein the central body is arranged with the first actuation arm and the second actuation arm are within the common valve housing.
 19. The safety valve device of claim 17, wherein each actuation arm is operatively engaged with a respective valve element, and the actuation portion is coupled to a third valve element.
 20. The safety valve device of claim 19, wherein the actuation arms are jointly actuable, and the actuation portion is movable independently of the actuation arms.
 21. The safety valve device of claim 19, wherein the valve elements of the first valve and the second valve are arranged in a direction that is opposite the direction of the valve element of the third valve. 